Many electronic devices, such as cellular telephones and personal digital assistants (PDAs), have the need for a digital camera to be included in the design. Such combined devices have been manufactured. The digital cameras for such combined devices are designed for general photography use. In addition to the primary lens in a digital camera, some models allow the use of accessory lenses. The use of accessory lenses is a common technique for changing the way the primary lens of the camera works. Such commonly used accessory lenses include wide angle, telephoto, and macro lens attachments.
Fingerprint recognition systems have also been developed. Incorporating a fingerprint recognition system into an electronic device provides security and authentication of the user. Existing fingerprint recognition systems use their own dedicated optics and image sensor for capturing images of fingerprints. Thus, for example, if a conventional fingerprint recognition system were incorporated into a digital camera, or a combined electronic device that included a digital camera, two independent sets of optics and image sensors would be needed.
It would be desirable to provide an accessory lens assembly that includes a lens/illumination system and a suitable surface for imaging a finger, and thereby be able to make use of the existing optics and image sensor of an electronic device that includes a digital camera to provide fingerprint recognition functionality.